Fuels for internal combustion engines such as diesel fuel, kerosene, light oil, bio-fuels or a combination thereof may include a wax component that is subject to crystallization (“waxing”) at temperatures below approximately −10 degrees Celsius. Suspended wax crystals can be trapped by or adhere to the filter media of a fuel filter resulting in partial or complete blockage of the fuel filter. Such blockage of the fuel filter may result in interruption of fuel flow to the engine resulting in a reduction of engine output or stalling of the engine.
Attempts to alleviate waxing problems inherent with such fuels have involved the application of heating elements in the fuel system supplying the engine. Such heating elements may include fuel tank or fuel line heaters as well as engine block heaters or heat exchangers. Recirculation of heated fuel from the fuel injection system to the fuel tank has also been utilized. While these and other methods for avoiding waxing of the fuel have met with some success, the devices utilize significant energy thereby reducing the efficiency of the engine, are costly and may not operate rapidly enough, especially following a cold engine start because the entire volume of fuel is subject to heating rather than directly addressing the wax crystals suspended therein.
Accordingly, it is desirable to provide an apparatus that is effective to eliminate obstruction of fuel filters caused by fuel wax crystallization and that is efficient and effective across the entire operational temperature range of the engine.